Process and system for duplex rotary reformer

ABSTRACT

Methods and apparatuses for producing fuel and power from the reformation of organic waste include the use of steam to produce syngas in a Fischer-Tropsch reaction, followed by conversion of that syngas product to hydrogen. Some embodiments include the use of a heated auger both to heat the organic waste and further cool the syngas.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/847,798, filed Sep. 8, 2015, which claims the benefit of priority toU.S. Provisional Patent Application Ser. No 62/046,342, filed Sep. 5,2014, both of which are incorporated herein by reference.

FIELD OF THE INVENTION

Various embodiments of the present invention pertain to the conversionof waste materials into other forms of energy, and in some embodimentsto the conversion of waste materials into both combustible gas andelectricity, and further such inventions with significant sequestrationof carbon dioxide.

BACKGROUND OF THE INVENTION

There is a great need to destroy a wide range of solid organic wastestreams generated around the world and at the same time to convert thiscarbonaceous waste into useful hydrogen-rich syngas by a compact,inexpensive rotary reformer to: (1) drive a fuel cell and (2) feed aFischer-Tropsch unit—both to produce clean energy. The challenge andproblem with fuel cells has been their sensitivity to various unknownchemical poisons at parts per million levels coming from the wastestreams from harming the electrochemical catalysts of the hightemperature fuel cells. By comparison Flory-Huggins catalysts inFischer-Tropsch reactors (such as supported iron and cobalt-basedcatalysts) are less sensitive to poisons than fuel cells and are highlyexothermic.

CO+2H₂→1/n (—CH₂—)n (I)+HO(I) ΔH°₂₉₈=−231.1 kJ/mol

Conversion of syngas to methanol using copper catalysts in the gas phaseor liquid-phase catalysts are exothermic and also less sensitive topoisons.

CO+2H₂→CH3OH(I) ΔH°₂₉₈=−128.2 kJ/mol

There is syngas methanation that is exothermic:

2CO+2H₂→CH₄+CO₂ ΔH°₂₉₈=−247.3 kJ/mol

And there are many other exothermic reactions that can use syngas andpreferably produce useful high-carbon content chemicals of commercialuse.

These highly exothermic reactors produce high-grade useful energy. Someof them can convert syngas with enough exothermicity to makeelectricity, steam and heat. These exothermic reactors can substitutefor fuel cells.

What is needed are processes and systems for converting waste into fueland energy with increased efficiency. Various embodiments of the presentinvention provide such processes and systems that are novel andnon-obvious.

SUMMARY OF THE INVENTION

One embodiment relates to an improved rotary steam/CO₂ reformer thatuses an electrically heated gas-phase steam/CO₂ reformer insert as wellas hollow spiral flights around the rotary retort tube in which a solidorganic waste stream is converted to syngas that can be used for fuelcell or other non-combustive heat engines for electric power generationand the production of renewable hydrocarbon fuels.

Another embodiment also makes use of fuel cells for providing theprocess parasitic load and heat. Yet another embodiment uses exothermicchemical reactors using syngas to produce heat, such as byFischer-Tropsch. It can also relate to control or elimination of theemissions of greenhouse gases in the power recovery process with thegoal of producing energy in the future carbonless and energy intenseworld economy.

One aspect of this process train is an improved duplex non-combustivekiln that combines the functions of the conventional kiln, steam/CO₂reformer, and the high temperature filter into a single unit, with oneexemplary process shown in illustration as FIG. 1. The downstreamdesulfurizer/getter bed process units can thus operate at a lowertemperature.

This duplex rotary reformer according to another embodiment furtheraccepts the hot, light end gases from either or both the PSA units formaking hydrogen fuel as well as the light end gases that formerly werewaste products from the Fischer-Tropsch process and use this light endgases to provide additional heat to the duplex rotary reformer to makemore syngas to make more product.

Still further embodiments involve using duplex kiln helical spiralflights moving counter-current to the hot exit syngas in a process trainthat also serves as the heat exchanger. Some embodiments are disclosedthat will quench-cool the syngas down from 800 to 1100° C. (1500 to2000° F.) to the temperature range of the desulfurizer to 370° C. (700°F.). One aspect of still further embodiments is to quench the syngas sothat the undesirable PAHs, soot or heavy hydrocarbon recombinationreactions (i.e. “De-Novo”) that make dioxins and furans do not have timeto form, since they are kinetically limited. These recombinationreactions may involve multi-step polymerization and/or ring formationand are slowed as the temperatures are lowered.

Further inventive options include a non-combustive Brayton cycle turbineto recover energy from the high temperature gas, while cooling it forfeeding to both the Fischer-Tropsch unit to produce the high-carboncontent product for sequestering the carbon and the shift converter andpressure-swing absorber to produce hydrogen fuel.

The Fischer-Tropsch reactor, as discussed in detail herein, isexothermic and may produce quantities of steam for operating aconventional steam turbo-generator system for powering the plant.

Yet other embodiments of the present invention include variouscomponents and process path arrangements for calcination of organicmaterial substantially as shown in FIG. 2. Persons of ordinary skill inthe art can reasonably and logically infer that not all of thecomponents shown in this figure are necessary parts of any embodiment.

Yet other embodiments of the present invention include variouscomponents and process path arrangements for calcination of organicmaterial substantially as shown in FIG. 4. Persons of ordinary skill inthe art can reasonably and logically infer that not all of thecomponents shown in this figure are necessary parts of any embodiment.

Yet other embodiments of the present invention include variouscomponents and process path arrangements for calcination of organicmaterial substantially as shown in FIGS. 6A, 6B and 6C. Persons ofordinary skill in the art can reasonably and logically infer that notall of the components shown in these figures are necessary parts of anyembodiment.

Some embodiments of the present invention include the conversion of awaste stream by steam/CO₂ reforming to produce a syngas that is used ina Fischer-Tropsch reactor to produce energy, minimize GHG emissions andsequester the carbon of the waste at the same time.

Although various apparatus and methods will be described in detail,other embodiments of the present invention are not so limited, and caninclude, as examples, alternatives to: modify or change the helicalflight shape or arrangement; the method of removing the fine particulatefrom the syngas before it enters the electrically-heated steam/CO₂reformer; the porous filter plate; and heat transfer enhancements usingthe electrical heating elements. Also interchanging the syngas cleaningprocess units around while keeping the same functionality are coveredunder various embodiments. All such generalizations are covered by thisinvention.

It will be appreciated that the various apparatus and methods describedin this summary section, as well as elsewhere in this application, canbe expressed as a large number of different combinations andsubcombinations. All such useful, novel, and inventive combinations andsubcombinations are contemplated herein, it being recognized that theexplicit expression of each of these combinations is unnecessary.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages will become apparent from the followingand more particular description of the preferred embodiment of theinvention, as illustrated in the accompanying drawings in which:

In FIG. 1A shows a schematic concept of a duplex kiln according to oneembodiment of the present invention that can be followed by quench heatexchanger cooling rapidly the syngas, a desulfurizer/getter bed, and theBrayton turbine for providing electric power and superheated steam forthe duplex kiln and fuel cell for generating additional power. Thesyngas is then fed to both a Fischer-Tropsch (FT) reactor andShift/Pressure Swing Adsorption System renewable H2 fuel as well as anoption.

FIG. 1B shows the diagram of FIG. 1A with element numbers.

In FIG. 2 there is shown a process diagram that uses high moisturecontent sewage biosolids or biomass from agriculture or animal feedlots,according to one embodiment of the present invention.

In FIG. 3 is shown a mass balance block diagram for the process diagramof FIG. 2, which shows how the FT process that makes liquid fuel andparaffin wax product for carbon sequestration accomplishes recycling tothe process front end of CO₂ and the light hydrocarbons that can includemethane, ethane, ethylene, propane, etc. to avoid their emissions asgreenhouse gases (i.e. methane), and also recycling the lighterhydrocarbons to help maintain a higher H₂/CO ratio of the syngas neededfor FT. It also describes how a waste stream can be made to releaseenergy without having to burn the waste or the syngas. At the same timethe waste can be converted into use carbon-containing fertilizer,hydrogen fuel, and a carbon-sequestering, high-carbon content product ofcommercial value, such as unsaturated, high-density paraffin wax.

FIG. 4 is a process diagram and flow sheet showing a second exampleaccording to another embodiment of the present invention for recyclingCO₂ into the main steam/CO₂ reformer, R-7.

FIG. 5 is a block diagram showing the mass balance for the processdiagram of FIG. 4.

FIG. 6A is the front portion of a process diagram of a 25 ton per dayprocess according to one embodiment of the present invention using coaland waste mine methane as the feedstocks.

FIG. 6B is the FT portion of a process diagram of a 25 ton per dayprocess of FIG. 6A according to one embodiment of the present invention.

FIG. 6C is the steam superheater portion of a process diagram of a 25ton per day process of FIG. 6A according to one embodiment of thepresent invention.

FIG. 7 is a mass balance block diagram showing mass balance for theprocess diagram of FIGS. 6 when the feedstock is coal and methane makingthe FT product with essentially zero CO₂ emission.

In FIGS. 8A, 8B, and 8C, there are shown an improved duplex kiln thatincludes one or more of the functions of the conventional kiln,steam/CO₂ reformer, swirling fines to drop out, the high temperaturefilter, recovery of high temperature radial heat loss, and internalheating of helical spiral flights at the wall into a single unit.

FIG. 8A is a cross sectional view of a rotary reformer of FIG. 1Aaccording to one embodiment of the present invention.

FIG. 8B is a portion of the cross sectional view of FIG. 8A.

FIG. 8C is a portion of the cross sectional view of FIG. 8A.

Element Nomenclature

The following is a list of element numbers and at least one noun used todescribe that element. It is understood that none of the embodimentsdisclosed herein are limited to these nouns, and these element numberscan further include other words that would be understood by a person ofordinary skill reading and reviewing this disclosure in its entirety.These element numbers refer to FIGS. 1A, 1B, 8A, 8B, and 8C.

 1 duplex kiln  4 kiln tube wall, feedstock  6 waste stream  8 exit tube 10 rotary plates, bellows  12 pipe, gases  14 pipe, tube  16 gas stream 18 chute  20 gear  22 arrow  24 waste  26 helical spiral flights  30gas flowing, syngas  32 arrow  34 vanes  36 swirl region  38 flat wallregion  40 media filter  42 tumbling media  44 port  48 reactor  50reformer  52 cap   52A rotating sealing plates  52b rotating sealingplates  54 chute  56 hollow truss  58 structure  60 port, steam  80offgasses  82 electrical power  83 generator  85 heat engine  88 power 92 fuel cell  93 stream  94 syngas  95 off-gasses  98 reactor 100 unit102 off-spec streams 103 fuel 104 fuel 106 hydrogen fuel 108 gas 110flowpath 112 hot syngas 114 heat exchanger 116 waste heat 117 clean-upbeds 118 finished syngas 120 clean syngas 122 off-gasses 124 hydrogenfuel 126 PSA, process step 128 steam stream 130 steam 132 shiftconverter, process step

Element Nomenclature Process Diagram And Mass Balance Block Diagram

The following is a list of element numbers and at least one noun used todescribe that element. It is understood that none of the embodimentsdisclosed herein are limited to these nouns, and these element numberscan further include other words that would be understood by a person ofordinary skill reading and reviewing this disclosure in its entirety.This numbering system and nomenclature refers to FIGS. 2, 3, 4, 5, 6A,6B, 6C, and 7. It is further understood that on those same figures theuse of non-alphanumeric (i.e., the use of numbers without a letterprefix) refer to product streams being passed from one component toanother.

inputs outputs C-11 Compressor 1 atmos 360 psig C-13 Compressor 360 psig400 psig D-23 Stream Divider FT gas/liquid bottom Recycle gas E-32 SteamTurbine-Generator Steam, 260F, 660 psig Steam, 240F, 20 psig F-24 Flashtank/ Gas/ Separate gas separator liquid mix and liquids F-9 Flash tank/Gas/ Separate gas separator liquid mix and liquids F-12 Flash tank/ Gas/Separate gas separator liquid mix and liquids H-2 Heating Side of  88°F.  980° F. Heat Exchanger H-20 Heating Side of 375° F.  650° F. HeatExchanger H-6 Heating Side of 930° F. 1850° F. Heat Exchanger M-1 MixerRecycle, steam, Recycle, steam, biomass biomass M-21 Mixer syngas andparafins syngas and parafins M-27 Mixer All water All water M-31 MixerCO2 and light ends CO2 and light ends M-33 Mixer n/a n/a M-34 Mixer n/an/a M-5 Mixer Steam, syngas Steam, syngas M-60 Mixer n/a n/a P-25 Pumpwater P-35 Pump n/a R-19 FT Reactor Finished syngas Liquid hydrocarbonsR-3 Equilibrium Reactor biomass syngas R-20 Hydrocracking Reactor Heavyhydrocarbon Light hydrocarbons R-21 Hydrotreating Reactor Heavyhydrocarbon Light hydrocarbons R-7 Equilibrium Reactor Crude syngasFinished syngas S-10 Component Splitter Syngas & impurities impuritiesS-12 Component Splitter Wet syngas Water and dry syngas S-22 ComponentSplitter Light paraffins wax S-26 Component Splitter Gas and liquidSeparate gas/liquid paraffins paraffin S-30 Component Splitter Liquidparaffins Diesel product S-31 Component Splitter Liquid paraffins Watercondensate S-4 Component Splitter Syngas & solids solids T-17Distillation Tower Mixed paraffins Separated lights and heavy T-37 TankParaffin product V-18 Valve Paraffin pressure control X-14 Gas-to-gasHeat Exchanger Hot syngas Cool syngas X-15 Air Cooler Heat Exchanger Hotsyngas Cool syngas X-16 Gas-to-gas Heat Exchanger Hot paraffins Coolparaffins X-28 Gas-to-gas Heat Exchanger Hot paraffins Cool paraffinsX-29 Gas-to-gas Heat Exchanger Hot paraffins Cool paraffins X-8Gas-to-gas Heat Exchanger Hot syngas Cool syngas X-2 Gas-to-gas HeatExchanger Hot syngas Cool syngas X-6 Gas-to-gas Heat Exchanger Hotsyngas Cool syngas X-40 Gas-to-gas Heat Exchanger Cool paraffins Hotparaffins

DETAILED DESCRIPTION OF ONE OR MORE EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, such alterations and furthermodifications in the illustrated device, and such further applicationsof the principles of the invention as illustrated therein beingcontemplated as would normally occur to one skilled in the art to whichthe invention relates. At least one embodiment of the present inventionwill be described and shown, and this application may show and/ordescribe other embodiments of the present invention, and further permitsthe reasonable and logical inference of still other embodiments as wouldbe understood by persons of ordinary skill in the art.

It is understood that any reference to “the invention” is a reference toan embodiment of a family of inventions, with no single embodimentincluding an apparatus, process, or composition that should be includedin all embodiments, unless otherwise stated. Further, although there maybe discussion with regards to “advantages” provided by some embodimentsof the present invention, it is understood that yet other embodimentsmay not include those same advantages, or may include yet differentadvantages. Any advantages described herein are not to be construed aslimiting to any of the claims. The usage of words indicating preference,such as “preferably,” refers to features and aspects that are present inat least one embodiment, but which are optional for some embodiments.

Although various specific quantities (spatial dimensions, temperatures,pressures, times, force, resistance, current, voltage, concentrations,wavelengths, frequencies, heat transfer coefficients, dimensionlessparameters, etc.) may be stated herein, such specific quantities arepresented as examples only, and further, unless otherwise explicitlynoted, are approximate values, and should be considered as if the word“about” prefaced each quantity. Further, with discussion pertaining to aspecific composition of matter, that description is by example only, anddoes not limit the applicability of other species of that composition,nor does it limit the applicability of other compositions unrelated tothe cited composition.

What will be shown and described herein, along with various embodimentsof the present invention, is discussion of one or more tests orsimulations that were performed. It is understood that such examples areby way of example only, and are not to be construed as being limitationson any embodiment of the present invention. Further, it is understoodthat embodiments of the present invention are not necessarily limited toor described by the mathematical analysis presented herein.

Various references may be made to one or more processes, algorithms,operational methods, or logic, accompanied by a diagram showing suchorganized in a particular sequence. It is understood that the order ofsuch a sequence is by example only, and is not intended to be limitingon any embodiment of the invention.

This document may use different words to describe the same elementnumber. It is understood that such multiple usage is not intended toprovide a redefinition of any language herein. It is understood thatsuch words demonstrate that the particular feature can be considered invarious linguistical ways, such ways not necessarily being additive orexclusive.

What will be shown and described herein are one or more functionalrelationships among variables. Specific nomenclature for the variablesmay be provided, although some relationships may include variables thatwill be recognized by persons of ordinary skill in the art for theirmeaning. For example, “t” could be representative of temperature ortime, as would be readily apparent by their usage. However, it isfurther recognized that such functional relationships can be expressedin a variety of equivalents using standard techniques of mathematicalanalysis (for instance, the relationship F=ma is equivalent to therelationship F/a=m). Further, in those embodiments in which functionalrelationships are implemented in an algorithm or computer software, itis understood that an algorithm-implemented variable can correspond to avariable shown herein, with this correspondence including a scalingfactor, control system gain, noise filter, or the like.

This application incorporates by reference U.S. patent application Ser.No. 12/287,996, PROCESS AND SYSTEM FOR CONVERTING WASTE TO ENERGYWITHOUT BURNING filed Oct. 14, 2008, now issued as U.S. Pat. No.8,858,900, to the extent that US900 does not contradict informationpresented herein.

One embodiment relates to a process and system for an improved rotarysteam/CO₂ reformer in which a solid organic waste stream is firstconverted to a syngas. In some embodiments that syngas is combined witha second stage that exothermically produces renewable hydrogen for fuelcell electric power and/or a unsaturated fuel such as Fischer-Tropschdiesel No. 2, JP-8 or Jet-A, with a small ˜15% fraction as a highcarbon-content, carbon-sequestering product. In some embodiments theoverall process can be made energy positive without having to burn thewaste or the syngas and consume oxygen and have large carbon dioxideemissions.

One aspect of some embodiments of the present invention is to covermethods and process systems to convert waste to energy without burningthe waste, but to also sequester the carbon of the waste so carbon gasesare not released.

The composition of the syngas was determined in a recently completed gastest according to one embodiment of the present invention using the BearCreek Pilot plant where municipal solid waste was steam/CO₂ reformed tomake syngas. The syngas composition is shown in Table 1 below.

TABLE 1 Results from Pilot Plant Gas Test By Steam/CO₂ Reforming OfSolid Waste H₂ Hydrogen 62.71 vol % CO Carbon Monoxide 18.57 CO₂ CarbonDioxide 10.67 CH₄ Methane  7.58 C₂H₆ Ethane  0.48 C₃ TO C₆ Propanethrough hexane <0.01 C₆H₆ Benzene  <17 ppm COS Carbonyl Sulfide   4 ppmCS₂ Carbon Disulfide 0.05 ppm H₂S Hydrogen Sulfide   <5 ppm C₁₀H₈Naphthalene  2.6 ppb C₁₀H₇CH₃ 2-Methylnaphthalene ~0.6 ppb C₁₂H₈Acenaphthalene ~0.4 ppb C₁₂H₈O Dibenzofuran 0.36 ppb PCDF + PCDDPolychlorinated- 0.0041 ppt TEQ dibenzofurans + Dioxins

What has been found experimentally was that the syngas was rich inhydrogen and carbon monoxide and also pure. For fuel cells some of thepoisons, such as carbonyl sulfide, hydrogen sulfide, carbon disulfide,hydrogen chloride, and polychlorinated organics, were identified. ForFischer-Tropsch, methanol synthesis, methanation, etc., this syngas islikely acceptable.

Another aspect of power recovery in some embodiments is to reduce theenergy losses of the waste-reforming kiln. Some inventive processesinvolve a kiln, followed by a desulfurizer and a high temperaturefilter. The kiln can be operated at a high temperature, followed by aneven higher temperature steam/CO₂ reformer which is then followed by thedesulfurizer and high temperature filter.

Regarding Fischer-Tropsch, the challenge was to develop a process trainwhere the Fischer-Tropsch unit could produce enough high carbon product,such as in one example high density, unsaturated paraffin wax containinglittle hydrogen, so that the carbon in the waste feed would besequestered in this product, without carbon emissions leaving theprocess anywhere else. The Fischer-Tropsch train in some embodimentsalso produces steam for a steam-turbo-generator to make electricity fora process plant.

Now referring to FIGS. 1A, 1B, 8A, 8B, and 8C, the functionality of oneembodiment of FIG. 1 is combined into a single kiln to increase thethermal efficiency and reduce the cost. This design is referred to asthe Duplex Kiln 1, that combines the functions of the conventional kiln,steam/CO₂ reformer, swirl fines drop out, the high temperature filter,recover of high temperature radial heat loss, heating internal heatingof helical spiral flights at the wall into a single unit.

Referring to the duplex kiln 1 in FIG. 8A, the waste stream 6 is fedoxygen-free through the large entry pipe 14 combined with recycle lightgases through pipe 12. Also in FIG. 1A are the bellow sealing disk pair52A, 52B that seals while at the same time allowing for the syngas to beused to heat the helical spiral flights

This entry region remains stationary whereas the kiln tube wall 4,rotates as shown by arrow 22 and is sealed by means of a pair of bellowstensioned rotary plates, 10 where in the bellows applies pressure to thepair of rotating sealing plates, 52A at the left (from section A-A) and52B at the right (from section B-B) The tube 4 rotates powered by drivepinion gear 20. Note that the bellows 10 is at the cold end of theduplex reformer where this bellows will have longer life. The thermalexpansion is about 5″ typically and the bellows can accommodate thismovement, as well as the wide pinion drive gears. At the hot end of theDuplex reformer the drive pinion 20 is in a V-shaped gear arrangement tohandle the end thrust from thermal expansion. Now as the waste enterstube 14, the gaseous portion moves above the waste into the kiln as gasstream 16. Once inside the kiln rotating tube 4, the solids are droppedinto the bottom of kiln by chute 18. The waste solids 6 drop by thischute 18 onto the moving helical spiral flights 26 moving from left toright and carrying with them the waste 24. These helical spiral flights26 are hollow with the gas 30 flowing in their interior from right toleft, counter-current to the waste and leaving through gas exit tube 8.It can be seen that the hot gas 30 is received within the interior ofthe hollow spiral flights 26, thus heating these flights by convection.The hot gas 30 is substantially cooler as it leaves the hollow flightsthrough exit 8. It can be seen that the hot gas 30 and the wastematerial 6 move in opposite directions within kiln 1.

As the waste 24 is moved progressively to the right by the helicalspiral flights 26, it eventually enters a flat wall region 38 wherethere is a tumbling media 42 that helps break lumps of waste and helpsform an aggregate material that leaves the rotary kiln through chute 54.

The gases 16 enter the swirl region 36 where their flow trajectory isdriven into a curved flow by vanes 34A and 34B. In this region 36 thecurved flow trajectory velocity throws the particles downward as shownby arrow 32, so as to join with the other solids moving along flat wallregion 38 toward exit chute 54. It can be seen that a second set ofvanes 34B (as best seen in FIG. 8C) redirect gas 16 toward filter 40.These gases 16 with less fines pass through porous media filter 40 andenter the electrical heated reactor 48 that has interior disk and donutbaffles 46 which steer the flow to pass cross flow around thecylindrical heating elements 50 for improved convective heat transfer.

This reactor 48 does not rotate as it is fixed to the stationary regionof the kiln by fixation cylindrical structure 58 that is attached to thecylindrical, insulated cap 52B. As best seen in FIGS. 8A and 8C, cap 52Bincludes a plurality of through holes. The hole pattern allows thefinished syngas 30 to enter the helical spiral flights 26 and eventuallyleave this duplex kiln at exit pipe 8. Kiln 1 thus includes a heattransfer path in which the hot syngas flows in a direction opposite tothe general direction of the flow of the waste material 24. Theelectrically heated reactor 48 is further supported mechanically byhollow truss 56 through which superheated steam and optionally added CO₂is fed by port 60 and enters this reactor through port 44. This addedreactant gases help further drive the formation of the finished syngaswith improved conversion to thermodynamically equilibrium with aninternal residence time at temperature of around one-half to threeseconds.

In FIGS. 1A and 1B the duplex rotary steam/CO₂ reformer 1 is shown as itis placed into one embodiment of the waste-to-fuel and energy processingsystem. Some embodiments of the rotary reformer have an integral steamreformer 50 at the exit end which reduces expensive high temperaturepiping and the heat losses associated with such piping. Thebiomass/waste feedstock 4 enters the process around room temperature atthe left and exits the process at chute 54 on the right. The finishedsyngas 30 that is produced exits at the left at somewhat above roomtemperature, and is generally formed at the right in reactor 50. Thesolid biomass/waste enters at the left and is mixed together with warmlight end gases 12 from the downstream process units, such as gas 108from Fischer-Tropsch and/or Pressure Swing Adsorpber (PSA) off-gases 122from the hydrogen purification section shown as process steps 126 and132.

Now referring to the exit end to the right of the duplex rotarysteam/CO₂ reformer 1, the electrically heated, hot gas-phase mainsteam/CO₂ reformer 50 is inserted though the right side. Any inorganicsand solid carbon phases exit the duplex rotary reformer warm but not hotthrough exit pipe 54 that is configured to minimize entry of outsideair. Besides the electrical heating, there are three other means ofheating and supplying the endothermic heat needed to drive the steam/CO₂reforming chemistry: [1] warm recycled light end gases 12 as well as [2]hot power generation hot gases 80 from Brayton cycle heat engine and [3]hot power generation hot gases 93 from hot cathode nitrogen-richoff-gases. This hot gas heat enters the reformer 1 into the typical oventhat surrounds commercial kiln retort tubes that rotate. These gasespreferably do not enter with the recycled gases 12 that enter theprocess flow, since gases 12 should be oxygen-free. Hot fuel cell anodeoff-gases 95 containing unreacted H2 and CO plus CO₂ and lighthydrocarbons may be mixed into port 60 to enter the electrically heatedsteam/CO₂ reformer.

Referring to FIG. 1B, the finished syngas 30 from the duplex rotaryreformer 1 is next heated by heat exchanger 114 using waste heat 116from the duplex reformer 1, so that the hot syngas 112 enters theabsorber clean-up beds 117 for sulfur, mercury, chlorine, etc. removal.The cleaned, finished syngas 118 is now substantially ready for use inproduct production of fuels, hydrogen gas, and power. This clean syngas120 first enters the Shift Converter 132, then enriched with H2 in steam130 enters the PSA 126 for concentrating the hydrogen. Off-gases 122from the Shift Converter are recycled back 12 to the front end of theduplex reformer. The PSA in some embodiments produces hydrogen fuel,124. There is also a steam stream 128 that can be used in stream 60 toassist the electrically-heated reformer 50.

Additionally in FIG. 1B, this syngas 118 can be sent via flowpath 110down to the Fischer-Tropsch (FT) where it enters via 96 into the FTreactor 98 that produces the crude paraffinic hydrocarbon fuel 106. ThisFT reactor 98 is exothermic and produces high pressure steam that can beused in the Brayton cycle turbine/engine 85 to make electrical power 82via generator 83. Although what has been shown and described is the useof a Brayton cycle heat engine, it is further understood that any typeof heat engine, including, as an example, a Stirling cycle engine, iscontemplated. The hot turbine off gases 80 exiting engine 85 can be usedto heat the duplex reformer. The crude FT paraffinic fuel 106 isseparated and distilled in unit 100 into a naphthenic fuel like, Jet JP4and into FT Diesel No. 2 103, both of which can be sold. The off-specstreams 102 consisting mostly of wax and alcohols and steam can be usedto create steam that can be supplied in stream 60 in FIG. 1B for furtherreforming in the electrically heated steam/CO₂ reformer 50 to make moresyngas and eventually more product. Various embodiments of the presentinvention operate with a high carbon efficiency and high energyutilization and efficiency.

In FIG. 1B, the clean syngas remaining 94 enters a solid oxide fuel cell92 that converts electrochemically this syngas into electricity andpower 88 to drive the plant and also start up the plant when the fuelcell is run on natural gas or tank propane or diesel. This fuel cell 92anodically reacts some 85% of the syngas and the 15% left over gasconsisting of unreacted H2 and CO plus CO₂ can also be used to createsteam for use in stream 60. The cathode off-gas includes hot nitrogenand this can be used to further heat the duplex reformer via stream 93.

Referring to FIGS. 8A, 8B, and 8C, the thermal efficiency in someembodiments derives from inside of the rotary reformer (calcinerequipment) with the inserted spiral flights that are hollow and allowthe hot syngas to be counter-flowed from the right back out the entrythrough the rotary plate seal. This provides the heat for the solidsfeed and cools the syngas as well. In the center is a cyclonic swirlvane section 36 that helps drop out fine solids entrained in the gas.The fines drop into the inorganic solids left after initial steamreforming around 900-1100° F. The cleaned syngas passes through a meshfilter 40 and enter the high temperature main steam/CO₂ reformer that iselectrical heated. The hot syngas at 1800-2000° F. that exits is rich inhydrogen, as shown in Table 1. This hot finished syngas is then passedthrough the spiral flights 26 in counterflow direction to exit cooled atthe port 8 of the rotary reformer. This is generally about 15 wt % ofthe feedstock entering the process. High carbon efficiency is achievedvia the bottom exit. There is also the option of a rebar section thattumbles to break up any larger pieces of solids into an aggregate sizethe material that can be used as a 70-80% carbon rich, 0-10-10 slowrelease pellet fertilizer, thus sequestering this carbon in the groundand not resulting the release of GHG to the Earth's atmosphere.

EXAMPLES

The first example of one implementation of the process of FIG. 2 isshown in the mass balance block diagram of FIG. 3, which uses highmoisture content sewage biosolids or biomass waste steam fromagriculture or animal feedlots. The size of this plant simulated was 20dry tons/day, with all of the paraffin wax from the FT reactor and anybottoms of the distillation column being recycled back to be reformedagain to make more syngas that can be used to increase the amount ofdiesel produced. All of the CO₂ is recovered and also recycled,essentially eliminating release to the atmosphere.

In this case, the MSW feed has a 50% moisture content as shown in FIG. 3by the 1417 lbs/hr dry feed plus the 1417 lbs/hr of moisture shown assteam. The inorganics from the MSW are simulated using inorganic saltbased on the Ash content of the MSW determined by Ultimate/Proximateanalysis. The result is the 593.9 lbs/hr of total FT liquids productsteam made up of 45.8% naphtha and 54.2% diesel. This produces 100gal/dry ton of FT liquids, that is about 50% better than the competitiveFT Biomass-to-fuel plants.

Still further embodiments of the present invention include otherfeatures identified while performing this study. One such featureincludes that if the hydrocarbon stream 42 is recycled after the FTcompressor, the energy demand for this compressor can by reduced to 226kWe down from the 437 kWe. This identifies that the process is onlyslightly energy negative with the electricity produced from a steamturbine using the FT steam produced. Additional waste energy recovery insome embodiments yields a plant for biomass that is energy positive. Therest of mass balance is summarized in FIG. 3.

A system according to another embodiment of the present invention isshown in a second example feeding MSW containing higher value plasticsusing the computer process simulation of MSW with the rotary reformerand the high temperature main reformer, R-7, to produce byFischer-Tropsch both a naphtha and a diesel fuel with all the otherlighter and heavier hydrocarbons recycled back to the rotary reformer aswell as any CO₂ produced back to the main reformer. The process diagramand flow sheet is shown as FIG. 4.

The size of this plant simulated was 20 dry tons/day, with all of theparaffin wax from the FT reactor and any bottoms of the distillationcolumn recycled back to be reformed again to make more syngas that canbe used to increase the amount of diesel produced. In addition the CO₂offgas from the syngas cleanup steps and a little from the FT reactorare split with 30% being recycled to the main reformer in stream 9 touse this valuable carbon resource to further make more syngas and thusmore diesel. The remaining CO₂ is vented. A mass balance is summarizedin FIG. 5.

Note that the flows for this 20 dry ton/day case of MSW are in lbs/hr.The MSW feed has a 25% moisture content as shown by the 3334 lbs/hr dryfeed plus the 1720 lbs/hr of moisture shown as steam. The inorganicsfrom the MSW are simulated using inorganic salt based on the Ash contentof the MSW determined by Ultimate/Proximate analysis. The result is the647.5 lbs/hr of total FT liquids product steam made up of 42.5% naphthaand 57.5% diesel. This shows that it is possible to carry out thevarious recycles as discussed in the specification and variousembodiments and produce a product that is a high 132 gal/dry ton.

A still further embodiment includes that if the CO₂ steam is recycledafter the FT compressor, the energy demand for this compressor can byreduced to 347 kWe down from the 817 kWe. This indicates that a processaccording to one embodiment is nearly energy positive. The electricitycan be produced from a steam turbine operating from the high temperaturesteam produced from the highly exothermal FT reactor.

Yet a third example as shown in the process diagrams of FIGS. 6 involvesthe use of dirty coal mine with mine-mouth waste methane gases in stream13 as well as CO₂. The mass balance block diagram is shown in FIG. 7.

The coal feedstock stream was 2083 lbs/hr on dry basis, coal-mouthmethane at 1650 lbs/hr and the steam used 8540 lbs/hr, The coal ashcontaining minerals represented by SiO₂ was removed from the rotaryreformer at 380 lbs/hr. Recycle streams used were FT light ends at 3916lbs/hr and distillation tops at 350 lbs/hr. The water recovered from thesyngas cleanup (3710 lbs/hr) as well as from the FT reactor (4835lbs/hr) covered the water needs at the feed of 8540 lbs/hr. As theresult of this nearly full utilization of the carbon (some of theexceptions being for a small CO₂ vent stream of CO₂ of 48 lbs/hr andsmall amounts of inerts such as argon and nitrogen) the quantity of FTliquids produced (73.3% diesel and 17.4% naphtha) was about 3840 lbs/hr.Based the coal solids stream this was 380.6 gallons/ton or based on thetotal gas plus solids feed from the dirty coal mine was 212 lbs/hr,which is about three times larger than the competitive coal-to-fuelprocesses. One aspect of this high carbon efficiency is the use ofrecycles of carbon-containing streams to minimize the CO₂ vent stream tothe atmosphere. This CO₂ vent was so low that the plant came under theEPA trigger of less than 250 tons/yr.

The purpose of these three examples show the large improvements that arepossible using the various recycle streams to produce more syngas,adjust the H2/CO ratio, improve greatly the carbon efficiency, andproduce more FT fuels with a duplex rotary reformer that can acceptthese recycles all in a single, more cost-effective, higher thermalefficiency device.

Various other embodiments of the present invention pertain to thefollowing:

An improved design of an indirectly-heated rotary calciner that willaccept biomass and waste including organic material, carry outoxygen-free steam/CO₂ thermo-chemistry to make H2-rich syngas (40-65 vol% H₂),

and where the solids in the feedstock are heated from 20 to 700° C. asthey are conveyed through the rotary kiln by helical spiral flights thatare hollow and heated inside by counter-flowing hot gas from 700-1300°C. which assists in the vaporization, volatilization, and steam/CO₂reforming of the waste,

and where this syngas that is formed is partially cleaned of entrainedparticulates by a swirl vane arrangement to drop out fines as well as afilter plate to further collect and drop out finer entrainedparticulates,

and where this syngas formed is further reacted in anelectrically-heated steam/CO₂ reforming reactor to accomplish conversionto syngas, minimize the formation of carbon soot below 2% , methanebelow 7%, benzene below 6 ppm and dioxins and furans below 0.01 ppm.

and where this hot finished syngas is the source of helical spiralflight heating that provides the heat needed for the incomingbiomass/waste feedstock, and where any inorganic contaminates, such asmetals, glass, sand, and rock are broken and ground up to a finishedaggregate ranging in size from 2 to 10 mm diameter to leave the duplexreformer.

Yet another embodiment of the present invention pertains to an improveddesign of an indirectly-heated rotary calciner that will accept biomassand waste consisting of any organic material, carry out oxygen-freesteam/CO₂ thermo-chemistry to make H₂-rich syngas (40-65 vol % H₂),

and which can accept and steam/CO₂ reform a variety of recycled gasesfrom Fischer-Tropsch synthesis and separation process steps, and fromfuel cell anodic and cathode off-gases, and can be used to also makethermal energy sufficient to drive the process as well as electricalpower to run the plant.

While the inventions have been illustrated and described in detail inthe drawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly certain embodiments have been shown and described and that allchanges and modifications that come within the spirit of the inventionare desired to be protected. As one example, it is understood that stillfurther inventive combinations are disclosed in combinations of any ofthe originally-filed independent claims as combined with one or more ofany of the originally-filed dependent claims, such as claims originallydependent on one independent claim also being considered in combinationwith any of the other originally-filed independent claims.

While the inventions have been illustrated and described in detail inthe drawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly certain embodiments have been shown and described and that allchanges and modifications that come within the spirit of the inventionare desired to be protected.

What is claimed is:
 1. An apparatus for calcination of organic material,comprising: a kiln including first and second stationary ends and arotating midsection between the two ends, the first end including anentrance for organic material and an exit for syngas; a conveyor formoving organic material from the entrance toward the second end, saidconveyor being supported within the midsection, said conveyor includingan internal gas path that provides syngas to the exit; and anelectrically heated steam reformer supported at the second end, saidreformer including an inlet for receiving organic material and an outletfor providing heated syngas to the internal gas path, said reformerincluding a reactor receiving organic material from the inlet andproviding heated syngas to the outlet; wherein the flow of syngas fromthe outlet of said reformer through the internal gas path to the exittransfers heat into said conveyor and said heated conveyor transfersheat into the moving organic material.
 2. The apparatus of claim 1 whichfurther comprises at least one turning vane proximate to the inlet ofsaid reformer, said vane being adapted and configured to separate solidinorganic material from the organic material prior to being received insaid reactor.
 3. The apparatus of claim 1 which further comprises agrinding region located within the midsection that receives solidinorganic material, said grinding region including tumbling media tocrush the solid inorganic material, the crushed material being providedto a chute supported at the second end of said kiln.
 4. The apparatus ofclaim 1 wherein said conveyor is a helical conveyor rotatable with themidsection.
 5. The apparatus of claim 4 wherein the internal gas pathextends down the central hub of the helix shape.
 6. The apparatus ofclaim 5 wherein the internal gas path extends within the spiral arms ofthe helix shape.
 7. The apparatus of claim 4 wherein the helicalconveyor is affixed to an interior of the midsection.
 8. The apparatusof claim 7 wherein the internal gas path is formed between the interiorof the midsection and the helical conveyor.
 9. The apparaus of claim 1which further comprises a heat exchanger that receives the syngasflowing out of the exit of said kiln and reheats the syngas with wasteheat from said kiln.
 10. The apparatus of claim 9 which furthercomprises a shift converter that receives at least a portion of thereheated syngas from the heat exchanger for shift conversion of the someof the reheated syngas to hydrogen.
 11. The apparatus of claim 9 whichfurther comprises a pressure swing adsorber that receives at least aportion of the reheated syngas and separates a carbon dioxide portion ofsaid reheated syngas.
 12. The apparatus of claim 11, wherein theseparated carbon dioxide portion is returned from the pressure swingabsorber to the kiln.
 13. An apparatus for calcination of organicmaterial, comprising: a kiln including first and second stationary ends,the first end including an entrance for organic material, said kilnincluding an exit for syngas; a helical conveyor for moving organicmaterial from the entrance toward the second end, said conveyor beingrotatable relative to the first end, said conveyor including an internalgas path in fluid communication with the exit; and a heated steamreformer supported within said kiln, said reformer including an inletfor receiving organic material and an outlet for providing heated syngasto the internal gas path, said reformer including a reactor receivingorganic material from the inlet and providing heated syngas to theoutlet; wherein the flow of syngas from the outlet of said reformerthrough the internal gas path to the exit transfers heat into saidhelical conveyor and said heated conveyor transfers heat into the movingorganic material.
 14. The apparatus of claim 13 which further comprisesa heat exchanger that receives the syngas flowing out of the exit ofsaid kiln and reheats the syngas with waste heat from said kiln.
 15. Theapparatus of claim 14 wherein at least a portion of the reheated syngasflows into a reactor for shift conversion of the some of the reheatedsyngas to hydrogen.
 16. The apparatus of claim 14 wherein a carbondioxide portion of syngas exiting the reactor is separated by a pressureswing adsorber.
 17. The apparatus of claim 16, wherein the separatedcarbon dioxide portion is returned from the pressure swing absorber tothe kiln.
 18. The apparatus of claim 13 wherein at least a portion ofthe syngas flowing from the exit of said kiln is received in aFischer-Tropsch reactor.
 19. The apparatus of claim 18 which furthercomprises a heat engine driving an electric generator, wherein steamgenerated in said FT reactor is provided to power said heat engine. 20.The apparatus of claim 19 wherein said steam reformer is electricallyheated, and electricity from said electric generator is provided to saidsteam reformer.